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United States Patent |
5,080,244
|
Yoshino
|
January 14, 1992
|
Synthetic resin thin-walled bottle and method of producing same
Abstract
This invention provides a synthetic resin thin-walled bottle, a tubular
intermediate therefor and a method of producing a thin-walled bottle. The
thin-walled bottle has ribs at least at its bottom portion, and the bottle
bottom is raised up frusto-conically or has an undulatory shape. The
tubular intermediate is first formed with ribs which become thin-walled
protuberant ribs after blow molding. The thin-walled bottle is produced by
blow-molding the ribbed tubular intermediate.
Inventors:
|
Yoshino; Yataro (Tokyo, JP)
|
Assignee:
|
Yoshino Kogyosho Co., Ltd. (Tokyo, JP)
|
Appl. No.:
|
359683 |
Filed:
|
May 31, 1989 |
Foreign Application Priority Data
| Nov 07, 1978[JP] | 53-137419 |
| Nov 24, 1978[JP] | 53-145689 |
| Nov 24, 1978[JP] | 53-145690 |
| Dec 04, 1978[JP] | 53-149871 |
| Dec 11, 1978[JP] | 53-153313 |
| Dec 18, 1978[JP] | 53-158253 |
Current U.S. Class: |
215/375; 215/382; 220/606; 220/608; 220/609 |
Intern'l Class: |
B65D 001/02; B65D 001/42; B65D 023/00 |
Field of Search: |
215/1 C
220/606,608,609,604
|
References Cited
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3420924 | Jan., 1969 | Mason et al. | 264/541.
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3480168 | Nov., 1969 | Lee | 215/1.
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3514812 | Jun., 1970 | Evers | 215/1.
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3881621 | May., 1975 | Adomaitis | 215/1.
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3900120 | Aug., 1975 | Sincock | 215/1.
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3948404 | Apr., 1976 | Collins | 215/1.
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3961113 | Jun., 1976 | Marco | 264/521.
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3973693 | Aug., 1976 | Bocklehurst | 220/1.
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4108324 | Aug., 1978 | Krishnakumar et al. | 215/1.
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4134510 | Jan., 1979 | Chang | 215/1.
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4151249 | Apr., 1979 | Lee | 215/1.
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4170622 | Oct., 1979 | Uhlig | 264/520.
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4197954 | Apr., 1980 | Oltman | 215/1.
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4249666 | Feb., 1981 | Hubert et al. | 215/1.
|
4261948 | Apr., 1981 | Krishnakumar et al. | 215/1.
|
4334627 | Jun., 1982 | Krishnakumar et al. | 215/1.
|
Foreign Patent Documents |
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293908 | Oct., 1971 | AT.
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301379 | Sep., 1972 | AT.
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1973838 | Sep., 1967 | DE.
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1801368 | May., 1969 | DE.
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882497 | Jun., 1943 | FR.
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2236634 | Feb., 1975 | FR.
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2435396 | Apr., 1980 | FR.
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3149264 | Dec., 1978 | JP | 215/1.
|
7309253 | Jan., 1974 | NL.
| |
7513287 | Nov., 1975 | NL.
| |
7703245 | Mar., 1977 | NL.
| |
7906151 | Aug., 1979 | NL.
| |
1114304 | May., 1968 | GB.
| |
1161572 | Aug., 1969 | GB.
| |
1177875 | Jan., 1970 | GB.
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1239531 | Jul., 1971 | GB.
| |
1360107 | Jul., 1974 | GB.
| |
1406958 | Sep., 1975 | GB.
| |
1441657 | Jul., 1976 | GB.
| |
1528512 | Oct., 1978 | GB.
| |
Primary Examiner: Weaver; Sue A.
Attorney, Agent or Firm: Oliff & Berridge
Parent Case Text
This is a division of application Ser. No. 06/677,333 filed Dec. 4, 1984,
now U.S. Pat. No. 4,997,692 which in turn is a continuation of appln. Ser.
No. 06/343,860 filed Jan. 29, 1982, now abandoned which in turn is a
divisional of appln. Ser. No. 06/089,537 filed Oct. 29, 1979 now
abandoned.
Claims
What is claimed is:
1. A biaxially oriented synthetic resin thin-walled container made by blow
molding an intermediate, comprising:
a top-open neck portion;
a closed bottom portion;
a hollow cylindrical barrel body portion interconnecting said neck portion
and said bottom portion;
the bottom portion having a plurality of hollow foot portions bulging
downwardly of the bottle, lower ends of the foot portions defining ground
contacting surfaces;
a plurality of solid rigid ribs being provided at least on an internal
surface of a bottom wall of the bottom portion, and extending radially
along an internal surface of the foot portions, said rigid ribs being a
result of a plurality of ridges provided on internal surfaces of said
intermediate prior to biaxial orientation.
2. A container according to claim 1, wherein a plurality of projections and
recessions, arranged alternatively in series and undulatory in sectional
shape, extend from the center of the bottom wall to the outer periphery of
the bottom wall, a difference in level between said projections and
recessions gradually increasing as the distance from the center of the
bottom wall increases, the foot portions being defined by a plurality of
said projections.
3. A container according to claim 2, wherein said rigid ribs are formed at
bends of each recession and projection.
4. A biaxially oriented synthetic resin thin-walled container made by blow
molding an intermediate, comprising:
a top-open neck portion;
a closed bottom portion which is bulged hemispherically downward;
a hollow cylindrical barrel body portion interconnecting said neck portion
and said bottom portion;
a plurality of solid rigid ribs being provided at least on an internal
surface of a bottom wall of the bottom portion, and extending radially
from the vicinity of the center of the bottom wall, said rigid ribs being
the result of a plurality of ridges provided on internal surfaces of said
intermediate prior to biaxial orientation.
Description
FIELD OF THE INVENTION
This invention relates to a synthetic resin thin-walled bottle,
particularly one formed with ribs at its bottom and/or other parts, and a
method of producing such a bottle.
DESCRIPTION OF PRIOR ART
Heretofore, glass bottles have been prevalently used as containers for
carbonated or refreshing drinks. However, because of their heavy weight,
they have a high required transportation cost and are also inconvenient to
handle. Generally, the container cost and transportation cost account for
a substantial portion of the price of such drinks, so that reduction of
these costs can greatly influence the total price of the product.
In order to overcome such problems, attempts have been made to use a
synthetic resin bottle which was reduced in wall thickness by means of
biaxial orientation and which was formed cylindrical at its barrel portion
and also bulged out spherically downwards at its bottom wall. Such bottle
although thin-walled, is provided with sufficient strength because of
biaxial orientation. However, since the bottom wall of the bottle is
bulged out spherically downwards, the bottom can not be placed upright
stably unless a skirt-like support member is additionally provided to the
bottle bottom portion. This results in an increased cost and marred
external appearance, and also if such support member is improperly fitted,
the bottle may tilt and, during the automatic pouring of a liquid, the
bottle mouth might be dislocated from the nozzle to cause improper
charging of the liquid.
Provision of a bulged leg portion at the periphery of the bottle bottom
wall may be conceived for effecting proper standing of the bottle, but in
such a case, insufficient strength exists at the bottle bottom portion
because the under side of the leg portion is excessively lessened in wall
thickness, making the bottle easily breakable.
OBJECTS OF THE INVENTION
The first object of this invention is to provide ridge-like ribs on the
bottle wall for assuring high strength of a synthetic resin bottle even if
it is thin-walled substantially in its entirely.
The second object of this invention is to form a frusto-conical raised-up
portion at the bottle bottom so that even when such raised-up portion
should be deformed during high-pressure charging of a liquid thereinto,
the ground-engaging portion of the bottle remains unaffected.
The third object of this invention is to undulate the bottle bottom portion
to increase bottle strength.
The fourth object of this invention is to provide a tubular intermediate
used for forming a ribbed thin-walled bottle.
The fifth object of this invention is to provide a method of producing a
ribbed, thin-walled bottle from an intermediate having the ribs on it.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut-away sectional view of a synthetic resin made
thin-walled bottle according to one embodiment of this invention;
FIG. 2 is a sectional view taken along the line II--II of FIG. 1;
FIG. 3 is a cross-sectional view of a bottle which is a modified version of
said first embodiment of the invention;
FIG. 4 is a sectional view of an intermediate used in the first embodiment
of this invention;
FIG. 5 is a partially cut-away sectional view of a thin-walled bottle
according to a second embodiment of this invention;
FIG. 6 is a partially cut-away perspective view of a thin-walled bottle in
accordance with a third embodiment of this invention;
FIG. 7 is a sectional view of an intermediate used in the third embodiment
of this invention;
FIG. 8 is a sectional view of a thin-walled bottle according to a fourth
embodiment of this invention;
FIGS. 9 and 10 are bottom views showing the different bottom configurations
of the fourth embodiment of this invention;
FIGS. 11, 12, 13 and 14 are sectional views of the principal parts of the
bottles which are modified versions of the fourth embodiment of this
invention;
FIG. 15 is a partially cut-away view of a thin-walled bottle according to a
fifth embodiment of this invention;
FIG. 16 is a sectional view of an intermediate used in the fifth
embodiment;
FIG. 17 is a bottom view of the embodiment of FIG. 15;
FIG. 18 is a partially cut-away view of a thin-walled bottle according to a
sixth embodiment of this invention;
FIG. 19 is a partially cut-away view of a thin-walled bottle according to a
seventh embodiment of this invention;
FIG. 20 is a view taken along the line XX--XX of FIG. 19 in the direction
of arrows;
FIG. 21 is a sectional view of the principal parts of a bottle which is a
modification of the seventh embodiment of this invention;
FIG. 22 is a sectional view taken along the line XXII--XXII of FIG. 21;
FIG. 23 is a partially cut-away sectional view of a thin-walled bottle
according to a modified version of said second embodiment of the
invention;
FIG. 24 is a sectional view taken along the line II--II of FIG. 23;
FIG. 25 is a cross-sectional view of a bottle which is a modified version
of the bottle of FIG. 23; and
FIG. 26 is a sectional view of an intermediate used in the embodiment of
FIG. 23.
DETAILED DESCRIPTION OF THE INVENTION
Now, the first embodiment of this invention is described with reference to
FIGS. 1 to 4. It will be seen that the biaxially oriented synthetic resin
thin-walled bottle 1 of this invention comprises, from bottom upwards, a
bottom wall 2, a cylindrical barrel portion 3, a shoulder portion 4 and a
neck portion 6 having formed thereon an external thread 5 to be engaged
with a cap. As for the material for the bottle of this invention,
saturated polyester resin is preferred, but it is also possible to use
other synthetic resins, such as polypropylene, vinyl chloride, etc., which
are capable of increasing the mechanical strength of the bottle by biaxial
orientation.
The bottom wall 2 of the bottle 1 is centrally bulged inwardly of the
bottle to form a frusto-conical portion or mountain-shaped rising 7. Thus,
the underside of the bottom portion between the lower edge of said portion
7 and the lower end of the barrel portion 3 forms the ground-engaging
section 8. On the inside of said ground-engaging section are provided a
plurality of ridged ribs 9 which are arranged radially as viewed from
above as shown in FIG. 2.
In case the wall thickness of the bottle is made extremely thin, the outer
end of each of said ribs 9 is extended along the axial line to an upper
part of the bottle barrel portion.
The above bottle may be formed in the following way. First, a bottomed and
top-open tubular intermediate 11 is formed by injection molding from a
synthetic resin which can be biaxially oriented. The neck portion 12 of
this tubular intermediate 11 is provided with an external thread 13 so
that it can immediately serve as the neck of the bottle. On the inside of
the bottom portion 14 of said tubular intermediate 11 are provided the
ridges 15 such as shown in FIG. 4. Such ridges 15 are provided in
plurality in radial arrangement from the center of the bottom, but no such
ridge may be provided in the central part because of formation of the
frusto-conical raised-up portion 7. The thus formed intermediate 11 is
heated to a temperature at which blow molding can be accomplished, and
then it is set in a blow molding die and while blowing compressed air
thereinto, the interior side of the bottom portion 14 of said intermediate
is pushed down by a push-down bar or other means to effectuate biaxial
orientation. The molding die used here is one which has an internal
configuration which allows formation of the desired external shape of the
thin-walled bottle 1.
In case the additional ridges 16 are provided around the lower part of the
intermediate 11, there will be formed the protuberant ribs 9, 17 on both
inside and outside of the bottle as shown in FIG. 3 to further increase
the bottle strength.
By forming the internal ribs by blow molding a parison, the external bottom
portion of the bottle remains smooth at the location of the internal ribs,
as shown in FIG. 1 and other figures described below.
Thus, the bottle of this invention is shaped cylindrical with small wall
thickness, but being biaxially oriented, it has high mechanical strength
and is light in weight. Also, since an inwardly projecting frusto-conical
portion 7 is provided at the bottom, the bottle can well withstand the
internal pressure which develops when a carbonated drink is charged into
the bottle under high pressure, and even if the raised portion 7 should be
deformed under such internal pressure, the bottle bottom won't swell out
spherically downwards as in the case of a flat-bottomed bottle, and hence
horizontality of the ground-engaging portion 8 of the bottle won't be
impaired. Therefore, the bottle won't tilt when it is placed upright, and
further, since a plurality of ribs 9 are provided radially (as viewed from
above) on the inside of the ground-engaging section 8 of the bottom wall,
the strength of the lower portion of the bottle is increased to provide an
extremely high impact strength at accidental drop of the bottle.
Referring to FIG. 5, there is shown a second embodiment of this invention
where the ridged ribs 9a formed at the bottle bottom portion extend to the
slant 7a of the frusto-conical portion 7 and also to the lower part of the
barrel portion 3 of the bottle thereby to increase resistance against
buckling load at the lower section of the bottle barrel portion.
A modification of this embodiment appears in FIGS. 23-26. The ridges 15
cross the bottom of the intermediate of FIG. 26. Upon blow-molding, this
creates a bottle as shown in FIGS. 23-25 in which the ribs 9 extend up the
slant of the frusto-conical portion 7.
A third embodiment of this invention is shown in FIGS. 6 and 7. In this
embodiment, the ribs 9b are formed extending along the full axial length
of the barrel portion as shown in FIG. 6, whereby the buckling strength is
greatly increased.
There are also provided ring-shaped annular constrictions 18 around the
lower part of the barrel portion 3. This can increase the stretch ratio of
the barrel portion 3 while elevating its strength owing to the rib
function.
The intermediate used in this embodiment is provided with long strips of
ridges 19 which extend along the axial line of the tubular intermediate
11. Such ridges 19 may be provided on the outer periphery of the
intermediate 11.
In FIGS. 8 to 14 is shown a fourth embodiment of this invention. In this
case, the bottle bottom portion 20 has its central part bulged inwardly of
the bottle to form a frusto-conical raised-up portion 21, with the base
part of said raised-up portion 21 being stepped to form a gentle rising
portion 22. This portion 21 may be either formed into a continuous
saucer-like part as shown in FIG. 9 or may be stepped radially at several
sections 22a as shown in FIG. 10.
As a modification of said fourth embodiment, the frusto-conical raised-up
portion 21 may be formed undulately by forming continuous recessions and
ridges alternately as shown in FIG. 11. As shown in FIG. 11, the width of
the recessions may be equal to that of the ridges. Also, stepped portions
25, as viewed in the axial direction of the bottle, may be formed at the
recessions 23 as shown in FIG. 12. In still other modifications, the
stepped portions 26 and 27 may be provided in both recessions 23 and
ridges 24 as shown in FIG. 13 or the stepped portions 27 may be provided
only in the ridges 24 as shown in FIG. 14.
Further, a plurality of protuberant ribs 28 may be formed radially from the
central part of the bottom wall, as viewed from above, on the interior of
the lower portion of the bottle, as shown in FIG. 8. In this case, the
strength of the bottle bottom is further increased if the protuberant ribs
are so provided as to extend to the slant 21a of the raised-up portion 21
and also to the lower part of the bottle barrel portion 3.
Thus, in the thin-walled bottle according to the fourth embodiment of this
invention, since a stepped region is formed at the lower end of the
raised-up portion, the surface area of the raised-up portion is more
enlarged than in the case of other embodiments, resulting in an increased
degree of stretching of the bottom wall and elevated rigidity of the
bottom wall owing to the rib function. For further increasing the strength
of the bottom wall of the bottle, the protuberant ribs are formed at the
pertinent area.
Now, a fifth embodiment of this invention is described with reference to
FIGS. 15 to 17. The bottom portion 29 of the thin-walled bottle is
provided with continuous jagged ribs 30 arranged radially from the center
of the bottom and undulatory in sectional shape. These ribs 30 are so
arranged that their height is zero at the center of the bottle bottom but
gradually increases toward the outer periphery, and the outer side of the
bottom portion of each said rib 30 is designed to form a ground-engaging
section 30a for allowing upright standing of the bottle.
Additional ridged ribs 31 are formed at the bends of each undulation formed
by the ribs 30 on the inside of the bottom portion of the bottle, said
ribs 31 extending down to the lower part of the bottle barrel portion.
Although no ribs 31 are provided at the central part of the bottle bottom
portion, they may be formed extending along the full vertical length of
the bottle barrel portion. Where no impediment is given to use of the
bottle, the ribs 31 may be also provided on the external surface of the
bottle to further increase its strength.
For forming the above-described thin-walled bottle, a tubular intermediate
33 having the ridges 32 is subjected to blow molding in a blow molding die
in the same way as Example 1, thereby forming a bottle having the radial
ribs 30 at the bottom.
The thus made thin-walled bottle is extremely enhanced in strength of its
bottom portion by dint of the ribs 30 at the bottom and the ridged ribs 31
at the bottom and barrel portion of the bottle. The ridged ribs 31 on the
interior of the bottle are provided as the ridges 32 formed on the
interior of the intermediate, and remain as they are after blow molding.
When the ridged ribs 31 are formed on the exterior of the bottle, blow
molding of the bottle becomes easier as there is no need of giving
consideration to formation of the ridged ribs on the interior of the
bottle. In this case, grooves corresponding to the ridged ribs 31 to be
formed are provided in the molding die.
Reference is now had to FIG. 18 for explaining the sixth embodiment of this
invention. In this embodiment, the bottom portion 34 of the bottle is
bulged out hemispherically downwards. Since the bottle is unable to stand
upright by itself, there is required a supporting leg member 35 that fits
with the bulging bottom portion of the bottle. It will be seen that the
top protuberant portion 36 of said leg member 35 fits with a corresponding
annular stepped portion 37 formed at the lower part of the bottle.
There are also provided on the interior of the bottle bottom portion 34 a
plurality of ridged ribs 38 arranged radially from the center of the
bottom portion. If necessary, such ridged ribs 38 may be extended all the
way to an upper part of the bottle.
In this embodiment, because of the hemispherical configuration, the bottom
portion of the bottle is very tough and also blow molding is facilitated.
Referring to FIGS. 19 to 22, there is shown a seventh embodiment of this
invention. In this embodiment, the central part of the bottom portion 39
of the bottle is bulged inwardly of the bottle to form a frusto-conical
raised-up portion 40 and the slant 41 thereof is formed undulately as
shown in FIG. 20. If the undulation on the slant 41 is formed extending to
the ground-engaging section 42 of the bottle bottom and to the lower part
of the bottle barrel portion 3, the lower portion of the bottle is made
more strong.
For increasing strength of the lower portion of the bottle, additional
ridged ribs 43 are formed at the crests of the respective waves or at the
bends between the waves in addition to said undulation extending from the
slant 41 to the ground-engaging section 42 of the bottle bottom and to the
lower part of the bottom barrel portion 3. The length of such ridged ribs
43 may be suitably determined depending on the desired bottle strength.
Ribs 43 are usually formed on the interior of the bottle, but where no
impediment is caused in use of the bottle, such ribs may be formed on the
outside of the bottle.
The thin-walled bottle of this embodiment can be formed in the same way as
Example 1 but by using a blow molding die having the undulatory hollows at
the part corresponding to the lower portion of the bottle.
The thin-walled bottle according to this seventh embodiment is increased in
degree of stretch at the lower portion of the bottle because of its
undulatory configuration and hence enlarged surface area. Further, the
bends between the waves can function as ribs, so that this bottle,
although thin-walled, can well withstand high pressure under which a
carbonated drink is charged thereinto. The frusto-conical rising at the
bottle bottom, coupled with the undulatory configuration, can further
enhance the stretch ratio.
If the thin-walled bottle of this invention is made from a saturated
polyester resin, there is no likelihood of any harmful substance such as
solvent remaining in the bottle in use and also no poisonous gas is
generated when the discarded bottle is burned.
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